The Australian Taxation Office (ATO) receives information from a wide range of third parties and uses data matching to compare it with what is reported in tax returns. In June 2026, the ATO reported that its data-matching program had adjusted more than 595,000 individual tax returns due to missing income, overstated deductions, tax credits and other discrepancies, highlighting the importance of reporting income correctly and keeping good records to support your claims. You can read more in the ATO’s announcement on its data-matching results.

What Information Can the ATO Receive?

Data matching involves comparing information held by the ATO with information received from other organisations.

Depending on your circumstances, this may include information relating to:

• Salary and wages
• Bank interest and investment income
• Shares and capital gains
• Rental properties
• Cryptocurrency transactions
• Contractor and business income
• Income earned through online platforms

You can read more about how the ATO uses data matching and its specific data-matching programs.

What about pre-filled information?

Pre-fill is one of the more visible ways taxpayers see information that has already been reported to the ATO.

Details such as salary and wages, bank interest, government payments and certain investment information may already appear when your tax return is prepared.

However, pre-fill should still be checked. It may not include everything, and information that does not appear in pre-fill may still be available to the ATO through its broader data-matching programs.

You can check the ATO’s pre-fill availability for more information.

Why Complete Reporting Matters

Data matching can help the ATO identify where information reported in a tax return differs from information it has received elsewhere.

Sometimes there may be a reasonable explanation for the difference. In other cases, income may have been overlooked or an amount reported incorrectly.

This is why it is important to tell your accountant about all relevant income and transactions rather than relying solely on what is already showing in ATO systems.

This is particularly important if you have investments, rental properties, cryptocurrency, foreign income, business or contractor income, or income from online platforms.

Good Records Support Your Deductions

Good record keeping is just as important when it comes to deductions.

Receipts, invoices, statements, logbooks and other supporting documents can help show why a deduction was claimed and how the amount was calculated.

In most cases, records supporting your tax return should be kept for five years from the date you lodge the return, although some records may need to be kept for longer.

The ATO provides more information about records you need to keep.

Do not rely solely on what appears in pre-fill or assume that income or a transaction will go unnoticed simply because it is not shown there. Keeping good records helps support the deductions you are entitled to, while providing your accountant with complete information can make tax time easier, reduce errors and support the figures reported in your return.